Structural or load-bearing components of buildings and structures, such as bearing walls or bridge supports, are constructed from a variety of materials including, but not limited to, wood, steel, and concrete. Concrete has many properties that make it ideally suitable for the construction of these structures, such as enhanced fire protection and durability, as well as favorable vibration and sound transmission characteristics. Traditionally, concrete structural or load bearing components are fabricated by cast-in-place techniques wherein the concrete is poured at the building site to form the components. Recently, however, the construction industry has seen an increasing use of prefabricated concrete building components where structural or load-bearing components are cast off-site and delivered to the construction site. Such prefabricated concrete components decrease construction times and can reduce the number of personnel at the building site, thereby resulting in an overall reduction of construction costs.
Because prefabricated concrete components are cast in a factory and transported to a building site, there is a significant need to create components that are strong enough for use in structural or load-bearing applications, but that are also lightweight and capable of resisting cracking and other damage that is associated with transportation. This need has been addressed by embedding materials into the prefabricated components during the casting process that not only make the components lighter in weight, but also serve to enhance their mechanical properties. In many precasting processes, particularly where structural or load-bearing components are involved, metallic mesh or reinforcing bars, such as rebar or high-tensile strength stainless steel, are embedded. Recently, however, other types of reinforcement materials have been substituted for metallic mesh and reinforcing bars with positive results. These materials include alkali-resistant glass, PVC, PVA, polypropylene, polyethylene, polyester, acrylic and kevlar, crysotile or crocidolite asbestos, high-modulus or high-strength carbon fibers, as well as natural fibers such as wood, sisal, coconut, bamboo, jute, akwara and elephant grass. As can be appreciated, these materials are typically lighter in weight than metallic mesh or reinforcing bars, display a greater degree of flexibility, and are also corrosion-resistant. Because embedding reinforcing materials such as these into prefabricated concrete components has successfully reduced their weight and enhanced their mechanical properties, the construction industry has also embedded these materials in cast-in-place applications where lighter weight concrete components with greater tensile strength are desired.
While embedding materials such as these into prefabricated concrete components has served to enhance the mechanical properties of the components and to make them lighter in weight, substantial expense can still arise from the labor costs and efforts needed to properly provide, position, and embed the reinforcement materials into the components during casting. Increased expenses are often associated with the fact that each step of providing, positioning and embedding typically occurs separately and each requires several workers to be properly accomplished, thereby increasing the time of manufacture, as well as the cost.